A state-wide construction blitz was announced by Premier Daniel Andrews on Tuesday and will see buses replace trains on the Warrnambool line for more than two weeks in April. 

The Warrnambool resident, who wished to remain anonymous, said half of Tuesday's four-hour journey was spent on an old, hot replacement coach. 

The 1.05pm service from Southern Cross station was cancelled and passengers were advised to catch a train to Geelong before boarding a bus to Warrnambool. 

The passenger said he jumped on a Geelong-bound service about 12.50pm and arrived in Warrnambool just before 5pm. 

He said the bus service between Geelong and Warrnambool was express but "very hot", with limited air conditioning and every seat filled. 

"The bus was air conditioned but it just couldn't keep up with how hot the bus was," he said. 

"Unfortunately this has become expected. The service is very inconsistent."   

The passenger said he last year endured a five-hour bus trip home from Melbourne, and on another occasion, nearly missed an international flight. 

"I went to catch the train one morning and ended up having to get my husband to drive me to the airport as I didn't really know how long the bus replacements would take," he said. 

The passenger said the constant delays were frustrating but noted that V/Line staff were sympathetic and apologetic.

The 5.43pm Warrnambool to Southern Cross train was also cancelled and replaced by road coaches for the entire journey on Tuesday. 

A V/Line spokesman said the cancellations were due to a broken windscreen on the locomotive that was scheduled to carry passengers from Southern Cross to Warrnambool and back. 

The 9.25pm Warrnambool to Southern Cross service was also cancelled due to a carriage fault. V/Line apologised to passengers and thanked them for their patience during the delays.

The Warrnambool line is undergoing $114 million upgrades, including a new crossing loop, signalling upgrades and track works.

And while the upgrades are expected to pave the way for high-speed VLocity trains, passengers have endured months of delays.

V/Line said temporary speed restrictions were in place as 45,000 sleepers were replaced along the line. The project started on September 4 and is nearing completion, with speed restrictions expected to be lifted by early March.

Buses will replace trains on the Warrnambool line between April 6 and 21. 

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